Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. A method for determining frequency correction and time slot boundary detection for synchronization in a wireless device, the method being performed in said wireless device, comprising: acquiring two occurrences of a plurality of cell broadcast frequencies in parallel; determining a subgroup of cell broadcast frequencies from said received plurality of cell broadcast frequencies, wherein at least one subgroup is determined for each one of said two occurrences of said plurality of cell broadcast frequencies; recovering frequency and time slot information in each said subgroup by tuning a local oscillator to a center frequency of each said subgroup; extracting individual frequencies from said recovered frequency information; and providing said individual frequencies to a frequency correction detector.
A method for synchronizing a wireless device involves the device acquiring two parallel instances of multiple cell broadcast frequencies, then determining subgroups within each instance. The local oscillator tunes to the center frequency of each subgroup to recover frequency and time slot information. Individual frequencies are extracted from this information and fed to a frequency correction detector for synchronization. This whole process is performed within the wireless device.
2. The method according to claim 1 , wherein said plurality of cell broadcast frequencies are received simultaneously.
A method for receiving multiple cell broadcast frequencies simultaneously in a wireless communication system addresses the challenge of efficiently monitoring multiple broadcast channels without requiring separate receivers or time-division multiplexing. The method involves a wireless device configured to tune to and process multiple cell broadcast frequencies at the same time, enabling real-time reception of broadcast messages across different networks or regions. This approach eliminates the need for sequential scanning or dedicated hardware for each frequency, improving power efficiency and reducing latency in message delivery. The technique is particularly useful in scenarios where a device must monitor broadcasts from multiple service providers or regions, such as emergency alerts, public safety notifications, or location-based services. By simultaneously receiving and processing these frequencies, the device ensures timely access to critical information without compromising performance or battery life. The method may also include filtering or prioritizing received broadcasts based on predefined criteria, such as signal strength, content relevance, or user preferences, to optimize resource usage. This solution enhances the reliability and efficiency of cell broadcast services in diverse wireless environments.
3. The method according to claim 1 , wherein extracting individual frequencies comprises: filtering said recovered frequency information; extracting in-phase and quadrature (IQ) samples by processing said filtered recovered frequency information by an analog-to-digital converter; receiving said IQ samples at baseband; and separating channels of the frequency information by de-rotating said IQ samples, thereby obtaining separate buffers for each individual frequency.
In the synchronization method from the first description, extracting individual frequencies involves several steps. First, the recovered frequency information is filtered. Next, an analog-to-digital converter processes this filtered information to extract in-phase and quadrature (IQ) samples. These IQ samples are then received at baseband. Finally, the channels of the frequency information are separated by de-rotating the IQ samples, creating separate buffers for each individual frequency, enabling channel-specific analysis.
4. The method according to claim 1 , further comprising: measuring a received signal strength indication (RSSI) for received absolute radio-frequency channel number (ARFCN) codes; and determining said plurality of cell broadcast frequencies to be acquired according to said RSSI and said ARFCN codes.
The synchronization method from the first description further improves frequency selection. The wireless device measures the Received Signal Strength Indication (RSSI) for received Absolute Radio-Frequency Channel Number (ARFCN) codes. The device then uses the RSSI and ARFCN codes to determine the cell broadcast frequencies to acquire. This focuses the acquisition on the strongest and most relevant signals.
5. The method according to claim 1 , further comprising: determining a plurality of subgroups, each having its own center frequency, and wherein said local oscillator is tuned to each center frequency in turn.
The synchronization method from the first description can determine multiple subgroups of cell broadcast frequencies, each with its own center frequency. The local oscillator is then tuned to each of these center frequencies in sequence. This allows the device to scan and process a wider range of frequency bands.
6. The method according to claim 1 , further comprising: detecting presence of FCCH in one of said individual frequencies.
In the synchronization method from the first description, after extracting individual frequencies, the method includes detecting the presence of a Frequency Correction Channel (FCCH) signal within one of those individual frequencies. This detection helps refine the frequency correction process.
7. The method of claim 1 , wherein each said subgroup comprises a first cell broadcast control channel carrier frequency and a second cell broadcast control channel carrier frequency, each of which has a corresponding frequency correction channel signal frequency at a frequency offset of 67.77 KHz, and wherein the frequency and time slot information is further recovered by identifying at least one of said corresponding frequency correction channel.
In the synchronization method from the first description, each subgroup of cell broadcast frequencies contains a first and a second cell broadcast control channel carrier frequency. Each of these carrier frequencies is associated with a corresponding frequency correction channel signal frequency, offset by 67.77 KHz. The frequency and time slot information is further recovered by identifying at least one of these corresponding frequency correction channels. This provides a precise method for frequency synchronization.
8. A wireless device for determining frequency correction and synchronization in the wireless device, comprising: a main receiver arranged to acquire a plurality of cell broadcast frequencies; an auxiliary receiver arranged to acquire said plurality of cell broadcast frequencies; and a processing unit arranged to: determine a subgroup of cell broadcast frequencies from said plurality of cell broadcast frequencies received by said main receiver; determine a further subgroup of cell broadcast frequencies from said plurality of cell broadcast frequencies received by said auxiliary receiver; recover frequency and time slot information in each said subgroup by tuning a local oscillator to a center frequency of each said subgroup; extract individual frequencies from said recovered frequency information; and provide said individual frequencies to a frequency correction detector.
A wireless device synchronizes by using both a main and an auxiliary receiver to acquire multiple cell broadcast frequencies. A processing unit determines subgroups of cell broadcast frequencies from each receiver's input. It then tunes a local oscillator to the center frequency of each subgroup, recovers frequency and time slot information, extracts individual frequencies, and provides them to a frequency correction detector.
9. The wireless device according to claim 8 , wherein said receiver is arranged to simultaneously receive said plurality of cell broadcast frequencies.
The wireless device for synchronization from the previous description has its main and auxiliary receivers simultaneously receiving the multiple cell broadcast frequencies. This allows for faster and more efficient acquisition of the frequency data needed for synchronization.
10. The wireless device according to claim 8 , wherein said processing unit is arranged to extract individual frequencies by: filtering said recovered frequency information; extracting in-phase and quadrature (IQ) samples by processing said filtered recovered frequency information by an analog-to-digital converter; receiving said IQ samples at baseband; and separating channels of the frequency information by de-rotating said IQ samples, thereby obtaining separate buffers for each individual frequency.
In the wireless device from the eighth description, the processing unit extracts individual frequencies through a series of steps. First, the recovered frequency information is filtered. An analog-to-digital converter processes this filtered information to extract in-phase and quadrature (IQ) samples. These IQ samples are received at baseband. Finally, the channels are separated by de-rotating the IQ samples, which creates separate buffers for each individual frequency.
11. The wireless device according to claim 8 , wherein said processing unit is further arranged to: measure a received signal strength indication (RSSI) for received absolute radio-frequency channel number (ARFCN) codes; and determine said plurality of cell broadcast frequencies to be acquired according to said RSSI and said ARFCN codes.
The wireless device for synchronization from the eighth description further enhances frequency selection. The processing unit measures the Received Signal Strength Indication (RSSI) for received Absolute Radio-Frequency Channel Number (ARFCN) codes. Based on these RSSI and ARFCN codes, the processing unit determines which cell broadcast frequencies to acquire, focusing on the strongest signals.
12. The wireless device according to claim 8 , wherein said processing unit is further arranged to: determine a plurality of subgroups, each having its own center frequency, and to tune said local oscillator to each center frequency in turn.
In the wireless device from the eighth description, the processing unit determines multiple subgroups of cell broadcast frequencies, each having its own center frequency. The local oscillator is then tuned to each of these center frequencies in turn, allowing the device to process a wider frequency range.
13. The wireless device according to claim 8 , wherein said processing unit is further arranged to detect presence of FCCH in one of said individual frequencies.
The wireless device for synchronization from the eighth description also includes a feature where the processing unit detects the presence of a Frequency Correction Channel (FCCH) signal within one of the extracted individual frequencies. This enhances frequency correction accuracy.
14. The wireless device of claim 8 , wherein each said subgroup comprises a first cell broadcast control channel carrier frequency and a second cell broadcast control channel carrier frequency, each of which has a corresponding frequency correction channel signal frequency at a frequency offset of 67.77 KHz, and wherein the frequency and time slot information is further recovered by identifying at least one of said corresponding frequency correction channel.
In the wireless device from the eighth description, each subgroup contains a first and a second cell broadcast control channel carrier frequency, each associated with a corresponding frequency correction channel signal frequency offset by 67.77 KHz. The processing unit recovers frequency and time slot information by identifying at least one of these corresponding frequency correction channels.
15. A nontransitory computer readable storage medium comprising a computer program for determining frequency correction and synchronization in a wireless device, the computer program comprising computer program code which, when run on the wireless device, causes the wireless device to: acquire two occurrences of a plurality of cell broadcast frequencies in parallel; determine a subgroup of cell broadcast frequencies from said received plurality of cell broadcast frequencies, wherein at least one subgroup is determined for each one of said two occurrences of said plurality of cell broadcast frequencies; recover frequency and time slot information in each said subgroup by tuning a local oscillator to a center frequency of each said subgroup; extract individual frequencies from said recovered frequency information; and provide said individual frequencies to a frequency correction detector.
A non-transitory computer-readable storage medium stores a program that enables a wireless device to synchronize. The program, when executed, causes the device to acquire two parallel instances of multiple cell broadcast frequencies, determine subgroups within each, tune a local oscillator to the center frequency of each subgroup to recover frequency and time slot information, extract individual frequencies, and provide them to a frequency correction detector.
16. The nontransitory computer readable storage medium according to claim 15 , wherein each said subgroup comprises a first cell broadcast control channel carrier frequency and a second cell broadcast control channel carrier frequency, each of which has a corresponding frequency correction channel signal frequency at a frequency offset of 67.77 KHz, and wherein the frequency and time slot information is further recovered by identifying at least one of said corresponding frequency correction channel.
The computer readable storage medium from the fifteenth description stores a program in which each subgroup comprises a first and a second cell broadcast control channel carrier frequency, each having a corresponding frequency correction channel signal frequency at a frequency offset of 67.77 KHz. When executed the program causes the device to recover the frequency and time slot information by identifying at least one of said corresponding frequency correction channel.
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September 19, 2017
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